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New Unit: EVOLUTION
EVOLUTION
 Evolution
is not a belief system. It is
a scientific concept. It has no role in
defining religion or religious beliefs
 Evolution
is a theory
How Evolution is Defined

“Evolution: The gradual process by which the present
diversity of plant and animal life arose from the earliest
and most primitive organisms, which is believed to have
been continuing for the past 3000 million years."
-Oxford Concise Science Dictionary

"evolution: ...the development of a species, organism,
or organ from its original or primitive state to its
present or specialized state; phylogeny or ontogeny"
- Webster's

"evolution: ...the doctrine according to which higher
forms of life have gradually arisen out of lower."
- Chambers
The definition I like and one that is
basic!!
“…evolution
can be precisely
defined as any change in the
frequency of alleles within a gene
pool from one generation to the
next."
What this definition means is....

Evolution is a change in the number of
times specific genes that code for specific
characteristics occur within an
interbreeding population

There is no implied “improvement” in
evolution
History of Evolutionary Thought
1707-1788: Buffon that creation provided
only a few small number of species that
evolved through natural processes
 1807-1873: Agassiz thought that new
creation arouse after each catastrophe
 1726-1797: Hutton Developed
Uniformitarianism in which slow natural
processes shape the Earth (eg. a small
stream could carve a valley)


1744-1829: Lamarck inheritance of
acquired characteristics (eg. an organism
passes on characteristics that it acquired
over its life time)
◦Giraffes got
their long necks
as a result of
needing to
stretch and
reach trees for
food
CHARLES DARWIN:

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1809-1882:
Charles Darwin was born on February
12, 1809 in Shrewsbury, England.
He observed much variation in related or
similar species of plants and animals that
were geographically isolated from each
other. (Patterns in Diversity)
He basically sailed around the world and
surveyed little known coastal areas
These observations were the basis for his
ideas.

Contrary to popular belief, Darwin was not the
first person to describe the concept of
evolution, but he was the one who gave it its
driving force.

“I have called this principle, by which
each slight variation, if useful, is preserved,
by the term Natural Selection.”
—Charles Darwin from "The Origin of Species“,
1859
Darwin develops his Theory:

Natural Selection: the process by which
certain heritable traits, those that make it
more likely for an organism to survive and
successfully reproduce—become more
common in a population over successive
generations. It is a key mechanism of
evolution!
We will look at some example cases
Pepper moth lab simulation

http://www.techapps.net/interactives/pepp
erMoths.swf
HOMEWORK
READ p. 296-302
 Do p. 299 #1, 3, 5, 6
 Word Wall Define: Extint
 Adaptation
 Mimicry
 Variations
 Mutations
 Selective advantage
